[1] Three-letter acronyms were used as mnemonics in biological sciences, from 1977[2] and their practical advantage was promoted by Weber in 1982.
[5] The specific generation of three-letter acronyms in computing was mentioned in a JPL report of 1982.
[6] In 1988, in a paper titled "On the Cruelty of Really Teaching Computing Science", eminent computer scientist Edsger W. Dijkstra wrote (disparagingly), "No endeavour is respectable these days without a TLA"[7] By 1992 it was in a Microsoft handbook.
[8] The number of possible three-letter abbreviations using the 26 letters of the alphabet from A to Z (AAA, AAB, ... to ZZY, ZZZ) is 26 × 26 × 26 = 17,576.
Allowing a single digit 0-9 increases this by 26 × 26 × 10 = 6,760 for each position, such as 2FA, P2P, or WW2, giving a total of 37,856 such three-character strings.